Mechanism for seat adjustment

ABSTRACT

A mechanism for controlling the positioning and motion of two relatively movable parts, such as a pivoted chair back and a chair seat for aircraft, busses, etc., comprising a slide bar having a lock device for holding it in any adjusted position, the lock device being releasable by a manually actuated control. The lock device includes a one-way override, which enables the slide bar to be moved in response to a force applied by its connection to a seat back when the seat is urged towards upright position. A spring acts on the slide bar to move it and the seat to seatupright position, and a pneumatic cylinder is connected to the slide bar to control its velocity, to avoid slapping the back of the seat&#39;&#39;s occupant by the seat back upon actuation of the control for the lock device. Adjustable limit stops are provided to determine the range of movement of the slide bar, and hence of the seat back. The mechanism is entirely mechanical, except for the noted pneumatic cylinder.

United States Patent 1 Pellman 51 Feb. 26, 1974 1 MECHANISM FOR SEATADJUSTMENT [75] Inventor: Ronald C. Pellman, Trumbull,

Conn.

[22] Filed: June 13, 1972 [21] Appl. No.: 262,372

[52] US. Cl 74/531, 297/375, 188/67, l88/82.3, 188/8284 [51] Int. ClA47c 1/02, B60m 1/06, GOSg 5/22 58 Field of Search 74/531; 188/67, 82.3,82.8, 188/82.84; 297/375 FOREIGN PATENTS OR APPLICATIONS Germany 297/375Primary Examiner-Allan D. I-lerrmann Attorney, Agent, or Firm-Irvin A.Lavine [57] ABSTRACT A mechanism for controlling the positioning andmotion of two relatively movable parts, such as a pivoted chair back anda chair seat for aircraft, busses, etc., comprising a slide bar having alock device for holding it in any adjusted position, the lock devicebeing releasable by a manually actuated control. The lock deviceincludes a one-way override, which enables the slide bar to be moved inresponse to a force applied by its connection to a seat back when theseat is urged towards upright position. A spring acts on the slide barto move it and the seat to seat-upright position, and a pneumaticcylinder is connected to the slide bar to control its velocity, to avoidslapping the back of the seats occupant by the seat back upon actuationof the control for the lock device. Adjustable limit stops are providedto determine the range of movement of the slide bar, and hence of theseat back. The mechanism is entirely mechanical, except for the notedpneumatic cylinder.

33 Claims, 8 Drawing Figures PMENTED E62 8 I974 SHEET 2 BF 3 PAIEmm m2 6I974 SHEET 3 OF 3 48 40 5060 70 I6 75 76 TI 82 2| FIG. 7

MECHANISM FOR SEAT ADJUSTMENT BACKGROUND OF THE INVENTION The presentinvention relates to a mechanism permitting the positioning of two partsrelative to each other, such as in connection with recliner-type seatingas used in aircraft, buses, and the like.

In a number of applications, a mechanism is desirable for releasablyholding two parts relative to each other in a number of differentadjusted positions, and this is true in particular in the field ofrecliner seats, wherein the seat back is pivotally connected to the seatbottom. More particularly, in the seating provided in aircraft andbusses, the pivoting of the seat back to the seat bottom is preferablyof the type allowing an infinite number of positions within the limitingrange, that is, between full upright and full reclined positions.Typically, a manual control device is provided for releasing a lock, thepassenger thereupon pushing against the seat back in order to cause itto move towards the full reclined position, releasing the manual controlwhen the desired reclined position has been obtained. The adjustingmechanisms heretofore known have not only provided the above features,but have also in some instances provided a spring for urging the seatback to the full upright position.

The heretofore known mechanisms provided with a return spring haveseveral deficiencies, however. Principally, these deficiencies includeinflicting discomfort to the passenger by virtue of the spring returningthe seat back to the upright position with such force that the passengeris back slapped. Another deficiency of the prior known adjustmentmechanisms has been the lack of any adjustability of the range ofmovement of the pivoted seat back.

Another important consideration in the provision of a mechanism of thisgeneral type has been that passengers have often left their seats withthe seat in the reclined position, thereby obstructing the passage ofpassengers occupying seats in the row rearwardly thereof. It wasthereupon the function of attendants, such as stewardesses, to restorethe seat to the upright position, and this could only be done in earlierconstructions, by having the attendant actuate the manual control inorder to release the locking means and to thereby permit movement of theseat back; however, it has been proposed to provide a mechanism whichenables the locking means to be released upon the application of a forceto the seat back to restore it to upright position, the seat backthereupon being permitted to be moved to the desired upright positionwithout actuation of the manual control. In a disclosed mechanism ofthis type, however, it was necessary to provide a separate actuatingmeans or control means for the locking means, which separate actuatingor control means was connected to the seat back through a lost motionconnection. Such mechanism was somewhat complex, due to the requirementthat there be a separate control means.

Control mechanisms which have heretofore been provided were of eitherthe hydraulic type, or the mechanical type. The hydraulic type includeda hydraulic piston and cylinder, and sealing was necessary, and obtainedthrough the use of seals of elastomeric material. These seals are knownto have a limited life, after which they are subject to leakage, withresultant defectiveness in operation of the mechanism. Also, it has beenfound that the typical movement of the piston rod in the seals resultsin the carrying on the surface of the piston rod a thin film of oil,which is subject to evaporation; as a consequence after a period of use,even without failure or deterioration of the seals, there is a decreasein the hydraulic oil or fluid contained in the device, with consequentloss of operating effectiveness.

SUMMARY OF THE INVENTION The present invention provides a mechanismpermitting the adjustment of relatively movable parts, particularly theseat bottom and seat back of a recliner type seat. This mechanism issubstantially entirely mechanical, except for a pneumatic cylinder,thereby avoiding the deficiencies of hydraulic type mechanisms of thisgeneral nature. The present mechanism is capable of locking the parts inan infinite number of positions, within the range of movement of theparts, and that range itself is capable of adjustment. The mechanismherein disclosed provides locking means for two relatively movable partsor elements, which locking means is subject to being unlocked orreleased by a manual control, so that these elements may be movedrelative to each other in either direction inside the movement range.Further, the present invention mechanism provides for an override torelease the lock to permit relative movement in one direction, inresponse to a force applied in that direction to one of the elements,thereby both permitting the pushing or pulling on a seat back to returnit to upright position and accomplishing this through a force applied tothe movable element directly, thus avoiding the necessity of a separatecontrol for the lock means. A further and important feature of thepresent invention is the provision of means to limit the velocity ofmovement of the movable element when the lock is released, to therebyavoid back slapping of the passenger where the mechanism is used inconnection with recliner seating. In addition, and significantly, thepresent invention provides for adjustment of the range of movement ofthe movable element forming a part of the mechanism.

The mechanism includes a housing which is attached to for example a seator seat bottom frame, and a slide bar of preferably rectangular crosssection which is attached to the seat back or seat back frame. A ramphaving inclined surfaces diverging from a center line overlies the slidebar;two rollers are provided, each being between a free surface of theslide bar and an inclined surfaces of the ramp. These rollers are urgedinto the triangular space thus provided by a spring, with consequentlocking of the slide bar against movement in either direction. A releasecam is provided capable of moving transversely of the slide bar andengaging the rollers, to cause them to move outwardly to thereby releasethe slide bar for movement in either direction, the release cam itselfbeing operable by manual control means which may take either of severaldisclosed forms. To provide for override of the above described lockingdevice including the double-inclined ramp and dual rollers, the ramp ispivoted laterally of the center line, and on the opposite side of thecenter line there is provided a roller stop in the inclined rampsurface. A ramp spring, preferably adjustable, urges the ramp about itspivotal connection towards the slide bar, and pivotal movement of theramp itself is limited by appropriate stops. As a consequence, a forceapplied to the slide bar to move it in a direction so that that rollerwhich is adjacent the roller stop is caused to engage that stop willresult in a limiting of the forces acting to prevent such movement ofthe slide bar and the slide bar will thereby move in the direction ofthe applied force because the applied force tending to cause itsmovement is greater than the reaction force due to the roller whichwould normally prevent such movement.

The ramp is further provided with a pair of additional ramp surfaceswhich lie more remotely from the ramp center line and are at a steeperangle, relative to the slide bar,than the first mentioned ramp surfaces.A pneumatic piston and cylinder assembly is provided, the cylindercarrying a pair of wedge surfaces which are positioned for engaging oneor the other of the remote ramp surfaces, or neither of them. The pistonof the pneumatic cylinder has a hollow piston rod with adjustablecontrol means in the form of a needle valve for controlling the flow ofair into and out of the cylinder chamber. The piston rod also carries agear which is in mesh with a rack in the mechanism housing and which isalso in mesh with a rack formed on the slide bar, and a spring engagesan end of the housing and the end of the piston rod. Therefore, thepiston rod-will move in the same direction as the slide bar, but foronly half the distance of movement thereof; in addition, an increase ordecrease of the pressure within the cylinder due to movement of thepiston will cause the cylinder to have a limited movement, butsufficient to engage one or the other of the wedge surfaces with one orthe other of the remote ramp surfaces. The wedges, or whichever of themis engaged, provides a force on the slide bar which is in opposition to,but less than the force causing the slide bar to move, with the resultthat there is a braking of the velocity of the slide bar to such anextent that the velocity of movement of the slide bar, and the seat backto which it may be connected, is limited. This prevents the above notedback slapping.

The slide bar itself is additionally provided with a guide element whichextends laterally of the axis of the slide bar, which guide elementmoves in a way provided between two apertured plates; pins may be placedbetween selected apertures, to thereby provide for adjustment of therange of movement of the slide bar, and therefore the seat back.

Other advantages of the present mechanism will become apparent from thefollowing description, when taken in conjunction with the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an elevational view of arecliner seat with the present mechanism applied thereto.

FIG. 2 is an elevational view of parts illustrating the basis of thepresent mechanism, in part.

FIG. 3 is a view similar to FIG. 2, but with modifications to providefor one-way override.

FIG. 4 is a further amplification of the apparatus illustrated in FIGS.2 and 3, and directed to the speed control feature.

FIG. 5 is an exploded view of the preferred embodiment of the presentinvention mechanism.

FIG. 6 is a longitudinal cross sectional view through the mechanismillustrated in FIG. 5.

FIG. 7 is an enlargement of a part of piston rod forming a part of themechanism shown in FIGS. 5 and 6.

FIG. 8 is a cross sectional view showing an alternate control for thepresent mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings,wherein like or corresponding reference numberals are used to designatelike or corresponding parts throughout the several views, there is shownin FIG. 1 a recliner-type seat generally designated 10, and which may beany one of such seats as presently used on aircraft and busses. The seat10 includes legs 11 and 12,a seat bottom 13 and a pivoted recliner back14. The adjustment mechanism is generally designated 15, and generallyincludes a housing 16 which is pivotally attached at 17 to the seatbottom 18 or to the frame which supports it. the mechanism 15 furtherincluding a slide bar 20 which is pivotally connected at its free end tothe lower end of the pivoted seat back 14. It is to be understood thatthe showing hereinabove described is illustrative, and that theattachment of the mechanism 15 may be to a seat formed other than seat10, may be attached in other ways to an appropriate seat, or may also beattached to other structure than a recliner seat. A control meansgenerally designated 25 has one end positioned towards the front of theseat 10 for ready manual actuation by an occupant of the seat, the otherend of the control 25 being connected with the mechanism 15.

In order to provide a disclosure of the basic principal of the presentinvention mechanism, there is shown in FIG. 2 a slide bar 20 and a fixedelement 30 with which the slide bar 20 is in engagement, and on whichthe slide bar 20 may be moved, either-to the left or right as shown inFIG. 2. Above slide bar 20,which is preferably of rectangular crosssection, is a ramp 40 having a first inclined surface 41 and a secondinclined surface 42, diverging from an apex 45. There are therebyprovided two generally triangular spaces between the ramp surfaces 41and 42 and the upper surface of slide bar 20. In each of the triangularspaces thus provided there are rollers 43 and 44; a formed wire spring46 urges the rollers 43 and 44 inwardly into the triangular spaces,towards the apex 45, spring 46 acting on lateral extensions of therollers. Assuming that the ramp 40 is fixed relative to the element 30,a force applied to the slide bar 20 to move it towards the left willcause the roller 44 to attempt to roll deeper into the triangular spaceto which it is located, towards the apex 45, but since the roller 44cannot move in that direction there will be a reaction force at thepoint where roller 44 contacts the upper surface of slide bar 20, whichforce will be normal to the slide bar 20, thereby forcing it against theupper surface of element 30. Taking into account a selected angle forthe surface 42 relative to the upper surface of slide bar 20 and themaximum static coefficient of friction between roller 44 and slide bar20, there will result a restraining force against movement of the slidebar 20 to the left which is larger than the force urging slide bar 20 tothe left. As a result, the slide bar 20 will not be able to move to theleft. As will be apparent, the same considerations apply in the case ofa force applied to move the slide bar 20 to the right, in which case theroller 43 and ramp surface 41 will act in the same manner.

The apparatus thus far described will be seen to prevent movement of theslide bar 20 in either direction, equally well, and it is apparent thatspring 46 serves only to keep the rollers 43 and 44 engaged with theirsurfaces, thereby preventing backlash, the locking effect above producedis self-energizing, and is not dependent upon the spring.

In order to provide for movement of the slide bar 20, a relase cam 37 isprovided for moving the roller 43 and 44 to a released or unlockedposition. Release cam 37 may be moved transversely of slide bar 20, andis provided with a pair of roller-engaging inclined surfaces 38 and 39.Consequently, movement of the release cam 37 in the upper direction willeffect displacement of rollers 43 and 44 away from each other and fromthe apex 45, so that when a force is applied to move the slide bar ineither direction, there will be no restraint or locking of slide bar 20due to the rollers 43 and 44 and the ramp surfaces 41 and 42,respectively.

Referring now to FIG. 3, the entire ramp 40 may be seen, including anear 47 extending from the surface opposite the apex 45, ear 47 beingprovided with an aperture receiving a pivot pin 48. Adjacent the apex 45there is provided a roller stop 42a on the inclined surface 42 of theramp 40. Further, a stop finger 49 extends laterally from the ramp 40 atthe right hand end thereof, and lies between a lower ramp stop 31 and anupper ramp stop 32. Stop 31 may be formed as a part of an integralextension of the element 30, and stop 32 may be formed as a part of aplate 34, which is fixed relative to the element and may, in fact, beintegral or secured thereto. The plate 34 is provided with a threadedopening 35 having a screw 36 therein, a ramp spring 50 extending in thebore 35 from the bottom surface of screw 36 into a recess 54 in the ramp40.

In operation, the ramp spring 50 will provide a clockwise force on ramp40, about pivot pin 48, and cause stop finger 49 to engage with lowerramp stop 31. It a force is applied to slide bar 20 to move it towardsthe right, the ramp 40 will pivot in a counter clockwise direction untilthe stop finger 49 engages the upper ramp stop 32, when the same lockingaction will occur in connection with roller 43, ramp surface 41 andslide bar 20 as was mentioned above in connection with FIG. 2. Incontrast, however, should a force be applied to slide bar 20 to move ittowards the left, roller 44 will be acted on by slidebar 20 and in turnwill act on ramp 40 so as to move the stop finger 49 towards upper rampstop 32, but will not engage it, due to the fact that roller 44 willengage roller stop 42a, thereby preventing further movement of roller 44to the left. Consequently, roller 44 can no longer tend to roll deeperinto the triangular space in which it is located, so that theselfenergizing action which is present in connection with roller 43 isno longer present in connection with roller 44. As a result, increasingthe force applied to slide bar 20 to move it to the left produces noconsequent reaction of the locking force urging the roller 44 againstslide bar 20 and slide bar 20 in turn against the element 30 andconsequently slide bar 20 will be permitted to move to the left by thenoted force applied directly to it. As a consequence, the mechanismdisclosed in FIG. 3 permits an override of the locking system when theslide bar 20 is moved to the left, but not when slide bar 20 is moved tothe right. In order to permit slide bar 20 to move to the right, meansmust be provided for moving roller 43 away from apex 45, such as therelease cam 37 shown in FIG. 2.

Depending upon the materials used, and therefore their coefficients offriction, and also dependent upon the angles of the surfaces 41 and 42,and assuming these to be fixed, as in a working mechanism, the actualforce required to be applied to slide bar 20 to move it to the left willbe dependent upon the adjustment of ramp spring 50 by the adjustmentscrew 36. Adjustment of the screw 36 to an outer position will result ina lesser force by spring 50 on ramp 40, so that a relatively small forcetending to move slide bar 20 to the left will be sufficient to effect anoverride, while adjustment of the screw 36 inwardly will have theopposite effect. Should the screw 36 be advanced into the bore 35 toeffect a stacked solid condition of ramp spring 50, it will be seen thatthe stop finger 49 will engage the lower ramp stop 31 and will beprevented from moving away from it. Thus, this adjustment of adjustment36 will prevent pivoting the ramp 40 about pivot pin 48 and the notedoverride capability of the mechanism will have been eliminated. In suchinstances, movement of the slide bar 20 can be effected only with arelease means such as the release cam 37 shown in FIG. 2. As aconsequence of the mechanism as disclosed in FIG. 3, override will bepermitted, the adjustment of the necessary override force can be made,and, alternatively, the override feature can be selectively eliminated.

Referring now to FIG. 4, there is shown a mechanism generally similar tothat of FIG. 3, but with the following additional structural features.The ramp 40 is provided with a pair of outer ramp surfaces 51 and 52,lying respectively outwardly of the aforementioned ramp surfaces 41 and42. A wedge-cylinder 60 carries a pair of wedges 61 and 62, wedge 61being provided with an inclined surface 61a having approximately thesame inclination as surface 51, and wedge 62 carrying a wedge surface62a having approximately the same inclination as ramp surface 52. Thewedges 61 and 62 are carried by an extension plate 63 that liesrearwardly of the ramp 40, and the wedges 61 and 62 may be integraltherewith. A slot 64 extends in extension plate 63, and receives axialextensions of rollers 43 and 44, to guide them in their movement.Extension plate 63 is connected to or integral with a pneumatic cylinder70, which may have a force applied to it to move it towards the right.As is clearly shown in FIG. 4, the wedges 61 and 62 are spaced asufficient distance apart so that the surfaces 61a and 62a thereof mayboth be out of contact at the same time with the outer ramp surfaces 51and 52 with which they may cooperate. This centering action results fromspring 46, which is supported on projections 67 and 68 extending from anextension plate (not shown in FIG. 4) which is parallel to extensionplate 63 and also connected to cylinder 70. Hence spring 46 centerswedges 61 and 62 out of contact with ramp surfaces 51 and 52.

In operation, assume that slide bar 20 is moving towards the left, andthat a force has been applied to the pneumatic cylinder so as to causeit, also, to move to the left. As a result of the movement of thepneumatic cylinder 70 to the left, the entire wedge-cylinder component60 will move to the left, so that the surface 62a of wedge block 62 willengage the outer ramp surface 52, and there will result a force on theupper surface of the slide bar 20, caused by the noted engagement ofwedge block surface 62a and outer ramp surface 52, and force beingapplied by the lower surface of the wedge block 62. This force will tendto restrain the movement of the slide bar 20, and therefore in effectwill produce a restraining force which is opposite in direction to theforce moving the slide bar 20 to the left. By giving consideration tothe materials used and the coefficients of dynamic friction thereof, andtaking into consideration the angle of the outer ramp surface 52 andwedge surface 62a, the restraining force on slide bar 20 can be selectedso as to be considerably larger than the force acting on the pneumaticcylinder 70 which tended to move the entire wedge-cylinder component 60to the left. However, this resulting restraining force will not be solarge as to generate a selflocking effect, such as that describedhereinabove with relation to the rollers 43 and 44. In effect, the outerramp surface 52 and wedge block surface 62a serve to amplify the forceapplied to pneumatic cylinder 70 to generate a larger restraining forcewhich opposes the motion of slide bar 20 in its movement to the left.

' cylinder 60 through the engagement of wedge block 61 with ramp 40,specifically outer ramp surface 51 thereof, and there will also beproduced thereby a restraining force on the slide bar 20. In both cases,therefore, there will result a net force on the slide bar 20 which willbe in the opposite direction as the force applied to it, but of a lessermagnitude. Hence, the force tending to move the slide bar 20 will havebeen significantly reduced, to thereby reduce its velocity.Consequently, where the slide bar 20 is connected to a seat back, sothat the slide bar 20 is moving, for example, to the left, and the seatback is moving to the upright position, the velocity of the slide bar 20and the seat back to which it is connected will be restrained and therewill thereby be avoided the above-mentioned back-slapping.

Referring now to FIG. 5, there may be seen an exploded, perspective viewof a preferred embodiment of a mechanism in accordance with the presentinvention. Thus, the housing 16 is shown, being generally hollow andhaving an end cap 18 for providing the pivotal connection 17 shown onFIG. 1. In order to accommodate the adjustment mechanism to various seatconstructions, it is contemplated that the end cap 18 may convenientlytake different forms, thereby avoiding any necessity to change the otherstructure of the mechanism 15. Abutting the end cap 18 (see also FIG. 6)is a slide bar actuating spring 19. Housing 16 also includes a rack 21.The slide bar 20, as best seen in FIG. 6 also is provided with a rack,22, the rack 21 of the housing and the rack 22 of the slide bar being inparallel, spaced and opposed relationship, with a gear 24 engaging andin mesh with both of the racks 21 and 22.

As is apparent from FIG. 5, the gear 24 is carried in a yoke 72 which ispreferably integral with a piston rod 71, yoke 72 having at its rear orright end a seat 73 for the spring 19.

Referring now to FIG. 6, the piston rod 71 may be seen to extend to theleft of the yoke 72, and to terminate in a piston 75. Piston 75 iswithin a pneumatic cylinder 70: pneumatic cylinder 70 forms a part of anintegral unit previously referred to, the wedge cylinder 60. Thus inFIG. 5, there may be seen the extension plate 63, extending to the leftof the pneumatic cylinder 70, and in spaced parallel relation thereto isa similar extension plate 65, the latter having a guide slot 66, and theformer having a guide slot 64: in these guide slots are axial extensionsof the rollers 43 and 44. Extension plate 65 is provided with a pair ofoutstanding cylindrical projections 67 and 68 which provide a mountingsupport for the spring 46.

The housing 16, which is basically channel-shaped in cross section, isprovided with a bottom closure plate generally designated 85, andincludes a pair of spaced parallel plates 86 and 87 having alignedapertures 88 therein, the plates 86 and 87 together define a way: aclosure cover 89 is preferably provided for the plates 86 and 87.Movable in the way provided by the plates 86 and 87 is a downwardlydirected extension 26 of the slide bar 20, and as best shown in FIG. 6,a pair of pins may be selectively positioned in any pair of alignedapertures 88 in the plates 86 and 87 to thereby provide for selectivelimiting of the range of movement of the slide bar 20.

Toward its left end, and underlying the ramp 40, the bottom closureplate 85 is provided with a pair of longitudinally extending slots 93and 94 which receive the release cam 37. Release cam 37 is in the formof a channel, the two arms of which extend into the slots 93 and 94 andthe roller-engaging inclined surfaces 38 and 39 thereof are provided onthe two portions of the release cam 37 formed by the channels thereof.Thus, the surfaces 38 and 39 on both arms of portions of the release cam37 engage axial extensions of the rollers 43 and 44 on the outer sidesof both of the extension plates 63 and 65. A release cam return spring37a is also provided, engaging the bottom closure plate 85 of housingThere may also be seen in FIG. 5 a U-shaped element 31, this being theabove referenced stop for the ramp 40, and there may be also seen thepivot pin 48 which extends through the side walls of the housing 16 andalso through the ear 47 of ramp 40. There is also provided an opening 96with closure plug 97 in one wall of the housing 16, to provide access tothe interior thereof, specifically to a control screw 76.

Referring now to FIG. 6, the hereinabove described parts may be seen inassembled relationship, there being clearly shown the spring 19, gear 24in mesh with racks 21 and 22, the piston rod 71 integral with the piston75 in the pneumatic cylinder 70, and the organization of thewedge-cylinder 60, the latter including the wedges or wedge blocks 61and 62. There may also be seen the ramp 40 with the pivot pin 48 andramp spring 50.

Referring now to FIG. 7, there is shown on an enlarged scale the piston75 with piston rod 71, the piston rod 71 being provided with the abovementioned control screw 76 having integral with it a needle valve 77,which thereby provides for adjustable control of the flow of air througha passage 78 extending in the piston rod 71, and communicating with theatmosphere within the housing 16, and with the interior of the pneumaticcylinder 70. In addition a branch passage 79 is provided having a checkvalve 81 therein to permit passage of air into the interior of thepneumatic cylinder 70, but preventing air from flowing from the interiorof pneumatic cylinder to the atmosphere. In series with the check valve81 is a control screw 82 having a needle valve 83 for adjustablycontrolling the rate of flow of air into the pneumatic cylinder 70through the branch passage 79.

The operation of the apparatus as specifically disclosed in FIGS. 5, 6and 7 will be described, bearing in mind the hereinabove provideddescriptions of the operations given in connection with FIGS. 2, 3 and4.

More particularly, in connection with the description of the operationof FIG. 4, reference was made to forces applied to the pneumaticcylinder 70. The force causing the wedge cylinder 60, includingpneumatic cylinder 70, to move to the left will be generated by thecompression of air within the pneumatic cylinder 70 when the piston 75is moved to the left, and piston 75 is moved to the left when the slidebar is moved to the left, this being the motion which occurs when theseat back 14 is being returned to the upright position. The movement ofthe piston 75 into the cylinder 70 compressed the air within thecylinder 70 increasing the pressure therein. There is provision forescape of the air from within pneumatic cylinder 70, this occurring pastthe control screw 76 with needle valve 77 thereon. Hence, the adjustmentof control screw 76 serves to determine the rate of pressureaccumulation within the pneumatic cylinder 70 for a given velocity ofmovement of the slide bar 20 to the left, it being understood that thismovement is generated by the spring 19 upon movement of the releasecam37. The control of the rate of pressure accumulation within thepneumatic cylinder 70 in effect controls the above mentioned force whichis applied to the wedge cylinder 60, to thereby engage wedge block 62with the ramp surface 52. The wedge 62 and ramp 40 thereby act toproduce the above mentioned amplified restraining force on slide bar 20to provide for control of its velocity. Obviously, the magnitude of therestraining force and therefore the velocity of the slide bar 20 can beadjustably controlled by adjustment of the control screw 76, for

movement of slide bar 20 to the left, and seat back 14 towards uprightposition.

It is to be further noted that the rate of pressure accumulation withinthe pneumatic cylinder 70, for given slide bar velocity, is related tothe instantaneous volume within the pneumatic cylinder 70. This volume,of course, reduces as the piston 75 advances to the left and the rate ofpressure accumulation concurrently increases. As a result, the hereinprovided apparatus serves to increase the instantaneouspressure-to-slide bar-velocity relationship as the piston 75 moves tothe left and this causes lower velocities of slide bar 20 as it movestowards the end of its travel, towards the left, as determined by thepin 91. That is, at the end of the movement of the slide bar 20approaching the seat upright position, there is a greater restrainingforce on slide bar 20, and thereby a lower velocity of it. This causesthe seat back to arrive at the upright position with a gentle or softstop, thereby preventing the back slapping above noted.

For movement of the slide bar 20 to the right, the gear 24, yoke 72 andpiston 75 will move to the right, thereby diminishing the pressurewithin the pneumatic cylinder 70. This generates a force on the wedgecylinder 60 causing it to move to the right, to thereby cause engagementof the wedge 61, and the amplification of a restraining force to themovement of slide bar 20. If the control screw 82 is moved to a positionwhere essentially the needle valve 83 does not function to restrictpassage of air into the pneumatic cylinder 70, the above described rateof pressure accumulation will be much lower: that is, because the airflow into the pneumatic cylinder will be substantially unrestricted, theforce acting to move the wedge cylinder 60 to the right will berelatively low, and therefore the restraining force applied to the slidebar 20 will be relatively low.

Thus, with the above noted adjustment of the control screws 76 and 82,the movement of the seat back 14 towards the upright position will bewith an ever diminishing velocity, because of the restrictedcommunication with atmosphere through the needle valve 77 and theblockage of communication through branch passage 79 by check valve 81,while in movement of the seat back towards the reclined position, therewould be the above noted substantially unrestricted flow into thepneumatic cylinder with a comparatively small restrining force on theslide bar 20. Thus, in movement towards seat reclining position, theretarding force will be comparatively low. As will be understood,however, in some applications, it would be desired to provide a controlfor movement of slide bar 20 to the right, and this can be achieved byadjustment of the control screw 82 to provide for restricted flow intothe pneumatic cylinder 70. It is further noted that movement by thepassenger of the seat back towards the reclined position is against theforce of the spring 19, so that there is in fact some resistance tomovement of the slide bar 20 to the right, due to the spring 19.

Further, it will be seen that the wedge cylinder 60 is normally inposition where neither of the wedges 61 or 62 engages the juxtaposedramp surfaces 51 and 52, respectively. Thus, it is in a centered orfloating condition, due to the noted action of spring 46 on projections67 and 68 of extension plate 65, and the control force, in eitherdirection, is basically proportional to the velocity of slide bar 20,and the force on slide bar 20 will be amplified by the cooperation ofwedge block61 or 62 and ramp 40 as described.

The control means 25, generally shown in FIG. 6 includes a piston 101,which is preferably a part of a bellows 102. Bellows 102 is fluidconnected with a conduit 103 which extends to a convenient portion ofthe seat 10, where there is a second piston 104 connected to bellows106. Thus pushing on the piston 104 will cause liquid to flow frombellows 106 through conduit 103 and into bellows 102, to thereby movepiston 10] and, with it, cam 37. Spring 37a will return the parts to theposition shown, upon release of piston 104.

In FIG. 8 there is an alternate control, generally designated 125. Ascrew 126 is carried in a housing 127, which is provided with internalthreads 128. A tangentially extending nipple 129 has secured to it aconduit 131, in which are a series of balls 132 which are in contactwith each other. A connector 133 serves to connect the conduit 131 withthe nipple 129, and there is provided therein a rod 134 which is adaptedto translate axially. The screw 126 is provided with a radiallyextending finger (not shown) near its bottom, which is engaged by rod134, and a suitable spring 136 has one end connected with the screw 126for causing it to move, rotationally, in one direction.

At the other end of the conduit 131 there is a housing 138 with aconnector element 139 having a second rod 141 therein. Within thehousing 138 is an actuator element 142, urged upwardly by the spring 143and having a control post 144 with cam surface 146, engaged by the endof the rod 141. Upon depressing of the actuator 142, the rod 141 will becaused to move to the right, moving with it the balls I32 which causethe rod 134 to move to the right, rotating the screw 126, and causing itto advance axially, to move the control cam 37 to the release position.Upon release of force from actuator 142, it will be returned by spring143, and the spring 136 will cause rotation of the screw 126 in theopposite direction, thereby pushing against the right hand end of therod 134, causing the balls 132 to move to the left, and to move, also,the rod 141 to the left.

It will be obvious to those skilled in the art that various changes maybe made without departing from the spirit of theinvention and thereforethe invention is not limited to what is shown in the drawings anddescribed in the specification but only as indicated in the appendedclaims.

I claim:

1. An adjustment mechanism for use with recliner seats comprising:

a first element, a second element in frictional engagement with saidfirst element and movable relative thereto in opposite directions,

means for releasably locking said second element against movement in afirst direction relative to said first element, said releasable lockingmeans comprising means responsive to a force of predetermined magnitudeapplied in one direction to said second element for releasing saidlocking means, and

control means for moving said locking means to a release position topermit relative movement of said elements.

2. The adjustment mechanism of claim 1, and further comprising means forurging said second element in one said direction, and means forretarding the movement of said second element in said one direction.

3. The adjustment mechanism of claim 2, and means operatively connectedto said second element for movement therewith for adjusting saidretarding means.

4. The adjustment mechanism of claim 1, wherein said second element is aslide bar, and said locking means comprises a ramp having a pair ofoppositely inclined surfaces adjacent said slide bar opposite said firstelement and a roller between said slide bar and each said inclined rampsurface.

5. The adjustment mechanism of claim 4, wherein said control meanscomprises means for moving each said roller to a position wherein itengages at most one of the slide bar and adjacentinclined ramp surfaces.

6. The adjustment mechanism of claim 4, means for supporting said rampfor movement toward and away from said slide bar, spring means urgingsaid ramp toward said slide bar, and roller stop means for limiting theextent of movement of one said roller in a slide bar locking direction.

7. The adjustment mechanism of claim 6, said spring means comprising aspring and adjustable pre-loading means therefor.

8. The adjustment mechanism of claim 7, wherein said spring is a coilspring and said adjustable preloading means comprises means for stackingsolid said coil spring.

9. The adjustment mechanism of claim 4, and further comprising springmeans for urging said slide bar in one direction, and means forretarding the movement of said slide bar in said one direction.

10. The adjustment mechanism of claim 9, said last mentioned meanscomprising an additional inclined surface of said ramp, a wedge block inengagement with said slide bar opposite said first element, said wedgeblock having an inclined surface in justaposition with said additionalinclined surface of said ramp, and

means for engaging said wedge block and the ramp surface injuxtaposition therewith concurrently with movement of said slide bar insaid one direction.

11. The adjustment mechanism of claim 10, wherein said ramp comprises asecond additional inclined surface inclined oppositely to said firstmentioned additional inclined surface, a second wedge block inengagement with said slide bar opposite said first element and having aninclined surface in juxtaposition with said second additional inclinedsurface, and means for engaging said second .wedge block and the rampsurface in juxtaposition therewith concurrently with movement of saidslide bar opposite said one direction.

12. The adjustment mechanism of claim 11, said last mentioned meanscomprising a pneumatic clyinder connected to said second wedge block.

13. The adjustment mechanism of claim 10, said last mentioned meanscomprising a pneumatic cylinder connected to said wedge block.

14. The adjustment mechanism of claim 1, wherein said second element isa slide bar, and further comprising spring means, and means connectingsaid spring means to said slide bar.

15. The adjustment mechanism of claim 14, said first element comprisinga housing, said connecting means comprising rack means on said slide barand on said housing, a gear in mesh with said rack means, and meansconnecting said spring means with said gear.

16. The adjustment mechanism of claim 14., and further including meansfor retarding movement of said slide bar', and means responsive tomovement of said slide bar for actuating said movement retarding means.

17. The adjustment mechanism of claim 16, said movement retarding meanscomprising wedge means engageable with said slide bar and a reactionmember.

18. The adjustment mechanism of claim 16, said actuating meanscomprising pneumatic piston and cylinder means, means operativelyconnecting the piston to said slide bar, and means responsive tononatmospheric pressure in said cylinder for moving said movementretarding means.

19. The adjustment mechanism of claim- 18, said pneumatic piston andcylinder means comprising adjustable port means communicating saidcylinder with atmosphere.

20. The adjustment mechanism of claim 18, wherein said pneumatic pistonand cylinder means comprises separate means for controlling the rate offlow of air into and out of the cylinder of said piston and cylindermeans.

21. The adjustment mechanism of claim 1, said control means comprising arelease cam, and manually controlled means for moving said release cam.

22. The adjustment mechanism of claim 21, wherein said last mentionedmeans comprises a closed fluid system including a manually operablepiston means, second piston means adjacent said release cam, and aconduit fluid connecting said piston means.

23. The adjustment mechanism of claim 21, said last mentioned meanscomprising a conduit having plural contacting spherical elementstherein.

24. The adjustment mechanism of claim 1, and further comprising meansfor limiting the range of movement of said second element.

25. The adjustment mechanism of claim 24, said last mentioned meanscomprising a lateral extension on said second element, means defining away for said extension, and adjustable blocking means extending fromsaid way-defining means transversely of the path of movement of saidlateral extension.

26. The adjustment mechanism of claim 25, said waydefining meanscomprising a pair of spaced, parallel plates having aligned aperturestherein, said adjustable blocking means comprising pins positionable inselected ones of said aligned apertures.

27. A mechanism for releasably locking a pair of elements comprising:

a. an axially movable slide bar,

b. a fixed element having a surface engaged by a surface of said slidebar,

c. reaction means comprising a ramp adjacent said slide bar oppositesaid fixed element, said ramp having a pair of ramp surfaces divergingfrom an apex adjacent said slide bar,

d. a pair of rollers each between said slide bar and a said surface foracting against said reaction means and said slide bar, and,

e. release means for moving at least one said roller in a direction awayfrom said apex.

28. The mechanism of claim 27, means for supporting said ramp formovement toward and away from said slide bar, spring means urging saidramp toward said slide bar, and roller stop means for limiting theextent of movement of one said roller in a slide bar locking direction.

29. The mechanism of claim 27, and further comprising spring means forurging said slide bar in one direction, and means for retarding themovement of said slide bar in said one direction.

30. A mechanism for use with recliner seats comprising:

a first element, a second element in engagement with said first elementand movable relative thereto in opposite directions,

means for releasably locking said second element,

control means for said locking means,

means for urging said second element in one direc tion and,

means for retarding the movement of said second element in said onedirection.

31. The mechanism of claim 30, and means operatively connected to saidsecond element for movement therewith for actuating said retardingmeans.

32. The mechanism of claim 30, wherein said retarding means comprisesmeans for retarding movement of said second element in either direction.

33. The mechanism of claim 30, said retarding means comprising means forapplying a retarding force proportional to the velocity of said secondelement.

1. An adjustment mechanism for use with recliner seats comprising: afirst element, a second element in frictional engagement with said firstelement and movable relative thereto in opposite directions, means forreleasably locking said second element against movement in a firstdirection relative to said first element, said releasable locking meanscomprising means responsive to a force of predetermined magnitudeapplied in one direction to said second element for releasing saidlocking means, and control means for moving said locking means to arelease position to permit relative movement of said elements.
 2. Theadjustment mechanism of claim 1, and further comprising means for urgingsaid second element in one said direction, and means for retarding themovement of said second element in said one direction.
 3. The adjustmentmechanism of claim 2, and means operatively connected to said secondelement for movement therewith for adjusting said retarding means. 4.The adjustment mechanism of claim 1, wherein said second element is aslide bar, and said locking means comprises a ramp having a pair ofoppositely inclined surfaces adjacent said slide bar opposite said firstelement and a roller between said slide bar and each said inclined rampsurface.
 5. The adjustment mechanism of claim 4, wherein said controlmeans comprises means for moving each said roller to a position whereinit engages at most one of the slide bar and adjacent inclined rampsurfaces.
 6. The adjustment mechanism of claim 4, means for supportingsaid ramp for movement toward and away from said slide bar, spring meansurging said ramp toward said slide bar, and roller stop means forlimiting the extent of movement of one said roller in a slide barlocking direction.
 7. The adjustment mechanism of claim 6, said springmeans comprising a spring and adjustable pre-loading means therefor. 8.The adjustment mechanism of claim 7, wherein said spring is a coilspring and said adjustable pre-loading means comprises means forstacking solid said coil spring.
 9. The adjustment mechanism of claim 4,and further comprising spring means for urging said slide bar in onedirection, and means for retarding the movement of said slide bar insaid one direction.
 10. The adjustment mechanism of claim 9, said lastmentioned means comprising an additional inclined surface of said ramp,a wedge block in engagement with said slide bar opposite said firstelement, said wedge block having an inclined surface in justaposItionwith said additional inclined surface of said ramp, and means forengaging said wedge block and the ramp surface in juxtapositiontherewith concurrently with movement of said slide bar in said onedirection.
 11. The adjustment mechanism of claim 10, wherein said rampcomprises a second additional inclined surface inclined oppositely tosaid first mentioned additional inclined surface, a second wedge blockin engagement with said slide bar opposite said first element and havingan inclined surface in juxtaposition with said second additionalinclined surface, and means for engaging said second wedge block and theramp surface in juxtaposition therewith concurrently with movement ofsaid slide bar opposite said one direction.
 12. The adjustment mechanismof claim 11, said last mentioned means comprising a pneumatic clyinderconnected to said second wedge block.
 13. The adjustment mechanism ofclaim 10, said last mentioned means comprising a pneumatic cylinderconnected to said wedge block.
 14. The adjustment mechanism of claim 1,wherein said second element is a slide bar, and further comprisingspring means, and means connecting said spring means to said slide bar.15. The adjustment mechanism of claim 14, said first element comprisinga housing, said connecting means comprising rack means on said slide barand on said housing, a gear in mesh with said rack means, and meansconnecting said spring means with said gear.
 16. The adjustmentmechanism of claim 14, and further including means for retardingmovement of said slide bar, and means responsive to movement of saidslide bar for actuating said movement retarding means.
 17. Theadjustment mechanism of claim 16, said movement retarding meanscomprising wedge means engageable with said slide bar and a reactionmember.
 18. The adjustment mechanism of claim 16, said actuating meanscomprising pneumatic piston and cylinder means, means operativelyconnecting the piston to said slide bar, and means responsive tonon-atmospheric pressure in said cylinder for moving said movementretarding means.
 19. The adjustment mechanism of claim 18, saidpneumatic piston and cylinder means comprising adjustable port meanscommunicating said cylinder with atmosphere.
 20. The adjustmentmechanism of claim 18, wherein said pneumatic piston and cylinder meanscomprises separate means for controlling the rate of flow of air intoand out of the cylinder of said piston and cylinder means.
 21. Theadjustment mechanism of claim 1, said control means comprising a releasecam, and manually controlled means for moving said release cam.
 22. Theadjustment mechanism of claim 21, wherein said last mentioned meanscomprises a closed fluid system including a manually operable pistonmeans, second piston means adjacent said release cam, and a conduitfluid connecting said piston means.
 23. The adjustment mechanism ofclaim 21, said last mentioned means comprising a conduit having pluralcontacting spherical elements therein.
 24. The adjustment mechanism ofclaim 1, and further comprising means for limiting the range of movementof said second element.
 25. The adjustment mechanism of claim 24, saidlast mentioned means comprising a lateral extension on said secondelement, means defining a way for said extension, and adjustableblocking means extending from said way-defining means transversely ofthe path of movement of said lateral extension.
 26. The adjustmentmechanism of claim 25, said way-defining means comprising a pair ofspaced, parallel plates having aligned apertures therein, saidadjustable blocking means comprising pins positionable in selected onesof said aligned apertures.
 27. A mechanism for releasably locking a pairof elements comprising: a. an axially movable slide bar, b. a fixedelement having a surface engaged by a surface of said slide bar, c.reaction means comprising a ramp adjacent said slide bar opposite saidfixed element, said ramp having a pair of ramp surfaces Diverging froman apex adjacent said slide bar, d. a pair of rollers each between saidslide bar and a said surface for acting against said reaction means andsaid slide bar, and, e. release means for moving at least one saidroller in a direction away from said apex.
 28. The mechanism of claim27, means for supporting said ramp for movement toward and away fromsaid slide bar, spring means urging said ramp toward said slide bar, androller stop means for limiting the extent of movement of one said rollerin a slide bar locking direction.
 29. The mechanism of claim 27, andfurther comprising spring means for urging said slide bar in onedirection, and means for retarding the movement of said slide bar insaid one direction.
 30. A mechanism for use with recliner seatscomprising: a first element, a second element in engagement with saidfirst element and movable relative thereto in opposite directions, meansfor releasably locking said second element, control means for saidlocking means, means for urging said second element in one directionand, means for retarding the movement of said second element in said onedirection.
 31. The mechanism of claim 30, and means operativelyconnected to said second element for movement therewith for actuatingsaid retarding means.
 32. The mechanism of claim 30, wherein saidretarding means comprises means for retarding movement of said secondelement in either direction.
 33. The mechanism of claim 30, saidretarding means comprising means for applying a retarding forceproportional to the velocity of said second element.